53 lines
1.6 KiB
GDScript
53 lines
1.6 KiB
GDScript
extends Node2D
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@export var speed = 400 # How fast the virus will move (pixels/sec).
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@export var attack_range = 200 # virus vision radius (pixels)
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# a virus is instantiated as Spawning and transitions (matures) into Spawned
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# after a timer timeout, after which it is activated and ready to do its thing.
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enum SpawningState {Spawning, Spawned}
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# when idle, a virus Waits. if it has already performed some action, it may
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# become Blocked for a while. otherwise it might be Running. like a process.
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enum ActionState {Blocked, Waiting, Running}
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var spawning_state
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var action_state
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var targets # who the virus will attack
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func _ready():
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self.spawning_state = SpawningState.Spawning
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self.action_state = ActionState.Waiting
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func _process(delta):
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if self.spawning_state != SpawningState.Spawned:
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return # do nothing if not yet spawned
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if len(self.targets) == 0:
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return # do nothing if no set targets
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# --- determine nearest target
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var nearest_target = self.targets[0]
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var shortest_distance = 0
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for i in range(1, len(self.targets)):
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var target = self.targets[i]
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var distance = self.position.distance_to(target)
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if distance < shortest_distance:
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shortest_distance = distance
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nearest_target = target
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# --- attack the nearest target, if within range
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if self.action_state != ActionState.Blocked:
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if shortest_distance < self.attack_range:
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self.attack(nearest_target)
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# --- move towards nearest target
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self.position += \
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self.position.direction_to(nearest_target) * self.speed * delta
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func attack(target):
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# do attack, block until timer
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self.action_state = ActionState.Blocked
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func _on_mature():
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spawning_state = SpawningState.Spawned
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